How to fire event from ComboBox inside StackPanel in WPF and MVVM - wpf

Question

I have ComboBox inside StackPanel. I am using MVVM and try to bind 'GotFocus' event Command to Command in ViewModel but when I Click on 'ComboBox', it don't work (It don't call Command in ViewModel) but if I move that 'ComboBox' out of 'StackPanel' it's working properly.
How can I fire event from 'CombBox' inside 'StackPanel' in MVVM?
<StackPanel x:Name="StackPanel" Grid.Column="2" Grid.Row="6">
<ComboBox x:Name="ComboBox" ItemsSource="{Binding Values}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<cmd:EventToCommand Command="{Binding Path=GotFocusCommand}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
</StackPanel>
ViewModel's code is:
public ViewModelCommand GotFocusCommand { get; set; }

Answer 1

////Change your tag from EventToCommand to InvokeCommandAction
<StackPanel x:Name="StackPanel" Grid.Column="2" Grid.Row="6">
<ComboBox x:Name="ComboBox" ItemsSource="{Binding Values}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<cmd:InvokeCommandAction="{Binding Path=GotFocusCommand}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
////Then, I use my commands this way in my view model:
private ICommand _GotFocusCommand;
public ICommand GotFocusCommand
{
get
{
if (_GotFocusCommand == null)
{
_GotFocusCommand =
new RelayCommand(
param => GotFocusCommand_Executed(),
GotFocusCommand_CanExecute
);
}
return _GotFocusCommand;
}
}
////RelayCommandClass.cs:
public class RelayCommand : ICommand
{
private Action _handler;
public RelayCommand(Action handler)
{
_handler = handler;
}
private bool _isEnabled;
public bool IsEnabled
{
get { return _isEnabled; }
set
{
if (value != _isEnabled)
{
_isEnabled = value;
if (CanExecuteChanged != null)
{
CanExecuteChanged(this, EventArgs.Empty);
}
}
}
}
public bool CanExecute(object parameter)
{
return IsEnabled;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
_handler();
}
}
////Finally, you can create an event in your view model:
private void GotFocusCommand_Executed()
{
//DoSomething here
}
private bool GotFocusCommand_CanExecute()
{
return true;
}